960. Упражняйтесь в быстром устном счёте:

1)

\(4 \times 4 \times 5 : 2 : 8 = 80 : 2 : 8 = 40 : 8 = 5\)

\(3 \times 3 \times 3 \times 3 : 9 = 81 : 9 = 9\)

\(4 \times 4 \times 4 : 8 : 8 = 64 : 8 : 8 = 8 : 8 = 1\)

\(5 \times 5 \times 3 : 5 : 5 = 75 : 5 : 5 = 15 : 5 = 3\)

\(6 \times 6 \times 2 : 4 = 72 : 4 = 18\)

\(7 \times 7 \times 2 : 7 = 98 : 7 = 14\)

2)

\(51 : 17 = 3\)

\(96 : 16 = 6\)

\(90 : 15 = 6\)

\(87 : 29 = 3\)

\(60 : 12 = 5\)

\(85 : 17 = 5\)

\(13 \times 6 = 78\)

\(24 \times 3 = 72\)

\(18 \times 4 = 72\)

\(29 \times 3 = 87\)

3)

\(14 \times 7 = 98\)

\(25 \times 4 = 100\)

\(6 \times 12 = 72\)

\(5 \times 17 = 85\)

\(69 : 3 = 23\)

\(84 : 4 = 21\)

\(68 : 4 = 17\)

\(42 : 3 = 14\)

\(78 : 6 = 13\)

\(85 : 5 = 17\)

Ответ: 1) 5, 9, 1, 3, 18, 14; 2) 3, 6, 6, 3, 5, 5, 78, 72, 72, 87; 3) 98, 100, 72, 85, 23, 21, 17, 14, 13, 17.